Last updated on September 22nd, 2023 at 08:28 pm
Banish black tank smells forever with these simple steps! Don’t be afraid to use your RV bathroom. Not having to use public restrooms or bathhouses when we travel is one of the reasons we love RV travel.
We’ve been living and traveling full-time in our RV for four years, using our bathroom just as we did in our sticks & bricks home. Even in the sweltering summer heat (we spent a couple in Florida), we were able to keep our bathroom and RV odor free by using the method we’ll outline in this post.
Continue on to read our step by step process or watch the video below.
Step 1. Keep the tanks closed until ready to flush.
If you are at a location with a sewer connection, you may be tempted to keep your camper’s black tank valve open and let the sewage flow freely. Don’t. This will result in the dreaded poop pyramid. Ever use an open pit toilet? You know the ones with no water at the bottom. Everything just starts building up. You need a lot of water to keep things flowing smoothly. In fact, I usually refill the toilet and give it an extra flush after most uses just to keep plenty of water in the tank. This will also help dissolve the toilet paper fully. Bottomline: Water is your friend and keep the tank valve closed until you are ready to dump.
Step 2. Flush the tank regularly.
It is important to flush your RV black tank regularly. This is easiest when you are at a campground with sewer hookups. We empty our black tank about every 5 – 7 days. If it is not 3/4 full, we add water to assist in completely draining the tank. We also recommend emptying it before travel to reduce the extra weight (water weighs ~8 lbs per gallon).
- Open the valve and drain the black tank completely.
- Back flush the camper’s black tank. Our main black tank has the built-in backflush inlet that most newer RVs come with. The black tank for the 2nd bathroom does not, so we purchased a Camco Dual Flush Pro Holding Tank Rinser. We backfill our tank for 4 minutes. Drain and repeat 1-2 times until the water is clear. I used to run inside and watch the tank monitor, but that got old so now I stay outside and time it.
- Once the water is running clear, close the black tank valve, and backfill the black tank with about 2 gallons of water. Since we have the built-in system, we just time it for 90 seconds. If you don’t have that, you can do it from inside by flushing the toilet and letting the water flow down into the holding tank for that long.
- We follow a black tank drain and flush cycle with a gray tank flush. We also have two gray tanks — one for the main bathroom (sink/shower) and one for the kitchen and the second shower. If are at a site with sewer hookups, we leave the main one closed until we’re ready to dump the black. We leave the 2nd gray tank open to drain as water is used. If you only have one gray tank and want to leave it open most of the time, we recommend closing it a day or two prior to your black tank flush so you can essentially wash out the sewer hose with the soapy gray water.
- Finally, when we get back inside the RV, we add two capfuls of Calgon water softener and about 1/2 cup to 1 cup of liquid dish detergent (some people say Dawn, but we use a generic).
Step 3. Remember, Water is Your Friend
As previously mentioned, using plenty of water is the best thing to keep the RV black tanks flowing smoothly. Don’t be afraid to use it. We both often flush an extra time or two just to add water to the holding tank.
Water availability was a problem we encountered with our first boondocking experience. Also, although we were able to use the portable sewage system, we didn’t have enough water available to back flush the tank as we described above. Our solution was to drive to a dump station every other week. In the future, we will book-end boondocking or partial hook-up stays with full hook-up campground stays.
Learn More About Your RV Water Systems
Check out our book, A Complete Novice’s Guide to RV Water System’s Maintenance you want to learn more about your RV water systems, from preventive maintenance like flushing the water heater to sanitizing the freshwater tanks. It’s short, full of photos, and written in laymen’s terms. Even better, it’s free on Amazon Kindle Unlimited!
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